How to repair a solar inverter

By Matthew Joseph Nandirio •  Updated: 10/04/21 •  5 min read

I will not lie on your face! Repairing a solar inverter is not something you can guess on and get right. These devices are pretty complex, and worse; they are prone to several issues. Similarly, not every guide out there will help you solves your problems. Should I remind you that not everyone who claims to be an expert is one!

We are sorry if we paved the way for fear in you! To make up for you, we have done our homework thoroughly on how to repair solar inverters. Therefore, we will give you all the details that might get your machine working again.

How can I fix a solar inverter?

A non-functional solar inverter means a dead solar system. Some of the issues can be easily identified by following troubleshooting mechanisms. Let’s look at some of these issues and how you can resolve them.

Inverter not charging

The solar inverter uses a battery. Despite the excellent maintenance of the inverter, they are prone to damages. Below are some tips to resolve inverter problems.

No power supply

If you notice that the inverter battery is not charging, the problem might be the power source or the battery itself. Thus, first, you should check if the socket is working by plugging on another device.

Next, check if the battery is correctly connected. Also, in some cases, the terminals can be corroded, which increases resistance. Thus, you should ensure that the connection is perfectly made and tight while the terminals should be clean and free from rust.

Further, the battery functionality may depreciate with time. As a result, it gets weakened and may discharge fast. In such a situation, you will have to replace the battery. However, if it uses liquid, for instance, lead acid-based batteries, you can pour out the liquid and replace it.

Blown fuse

If the battery and the plug are all working well and yet the inverter battery is not working well, you should check the input fuse, which might be blown. After ascertaining that the input fuse is not working, then you will have to replace it. While purchasing a new input fuse, you should ensure that its ratings are similar to the previous fuse. Else, you will destroy the inverter board.

Wrong frequency or input voltage

Solar inverters get the DC input from the photovoltaic cells of the solar panel. Also, these devices have a specific amount of input required before it gets to the current inversion process to AC. Consequently, if the input current is too high or low for the inverter, it will result in power fluctuation.

Bad inputs are corrected by using a voltage regulator on the input of the inverter.  On the other hand, if the frequency also is an issue, you will have to consult the utility supply authority to correct the values.

Inverter overheating

Inverter operations result in the production of heat. This heat should be dissipated to the outside environment using a fan, or worse, the components of the inverter may explode.  When the inverter starts to overheat, that means the fan is not functioning or else inefficient. Consequently, you should open up the inverter and repair or replace the fan.

Extreme vibrations

Inverters produce buzz sounds while functioning. However, if the sounds are extreme, they might be a red flag.  The inverter may vibrate highly if it is overloaded or facing bad voltages.

As we said earlier, bad voltages can be corrected by installing a voltage regulator. On the other hand, you should avoid overloading the inverter. Therefore, you should make correct calculations to ensure that you get the correct solar inverter for your power needs.

Inverter on bypass mode

On bypass mode, the inverter requires the mains to supply current to the load. Thus, when the main goes off, the inverter stops working.  The bypass mode is common if the inverter is not correctly powered on.

To power up the inverter, press the power button and wait until the inverter shows it is on or connects online. If it does not power on, try checking the dc circuit if it is broken or the signal cable is wrongly connected. To avoid such problems, always ensure that the connections are made correctly according to the manual.

Inverter returns power to the input.

A damaged AVR can cause the inverter to return power to the input instead of output. You can replace the AVR or get more advice from the manufacturer.

What is the cost of repairing an inverter?

The cost of repairing an inverter depends on the extent of the damage. In some cases, you can easily fix it with little guidance, while in other cases, the cost is dependent on the component to be repaired. In most cases, the repairing cost ranges up to $1,000.

How to replace a solar inverter

In some situations, you will have to replace a specific component of the inverter or replace the entire device. Replacing an inverter can cost approximately $2500. However, its replacement cost depends on the type of solar inverter and its capability.

Similarly, you may consider replacing a specific component to save you from the huge cost of getting a new solar inverter. Ideally, replacing solar inverter components cost approximately $500 t0 $800.

Final words

A solar inverter is the most critical component of a solar system. Consequently, in case it is damaged, you can’t benefit from your expensive solar system. This solar system component is prone to issues such as a damaged battery, bad voltages, failing to output the current much more.

This piece is a must-read for anyone with a non-functioning solar inverter. We have given solutions to help you repair solar inverters all by yourself. However, you can also hire a technician if you are not to do it. Don’t wonder how much that will cost! We have done our homework on an inverter’s repair and replacement cost to shed light on you. Also, you can check this linked manual.

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Matthew Joseph Nandirio

Matthew Joseph Nandirio is the Founder of walkingsolar. After graduating from the University of Houston in 2002, matt started working as an electrical and electronic engineer for several multi-national solar energy companies. He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research. He now shares his 20 years of expertise through his articles on the walkingsolar website. Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.